The First Human-Pig Hybrid Has Been Successfully Created In A Lab

Juan Carlos Izpisua Belmonte

In a move that can only be considered controversial, the first pig-human hybrid has been successfully created in a lab. Researchers managed to grow human cells inside early-stage pig embryos, which led to the creation of the first pig-human hybrids ever made. The result is described as interspecies chimeras.

Though the experiment is still in its early days, scientists think the “breakthrough” would possibly one day lead to lab-grown human organs that would be transplanted into people who need them. If the experiment is successful, hundreds of thousands of lives could be saved.

According to Science Alert, for the experiment, US scientists injected human stem cells in early-stage pig embryos. Then, the hybrid embryos were transferred into surrogate sows. The researchers were waiting until the embryos developed into the first trimester.

Finally, over 150 embryos developed into chimeras. Each one had produced the precursors of organs, including the heart and liver. Also, they contained a few human cells — about 1 in 10,000 of the hybrid cells was human.

As a team member, Juan Carlos Izpisua Belmonte, from the Salk Institute in California, said:

“Our findings may offer hope for advancing science and medicine by providing an unprecedented ability to study early embryo development and organ formation, as well as a potential new avenue for medical therapies.”

“We have shown that a precisely targeted technology can allow an organism from one species to produce a specific organ composed of cells from another species.”

Although reactions to the development have been mixed, it can't be ignored that science has leaped forward now that the first human-pig hybrid has successfully been created. Finally, the ethical implications need to be worked out.

Two years ago, Izpisua Belmonte along with his colleagues conducted experiments to create interspecies chimeras in the lab. The team managed to integrate human stem cells into mouse embryos, demonstrating that human stem cells can develop inside other species. They efficiently created a world-first chimera.

The word chimera comes from the Greek mythology and, according to legends, it used to be a monstrous, fire-breathing hybrid creature of Lycia in Asia Minor. It was made out of the parts of more than one animal. It was often depicted as a lion with a goat’s head sticking from the side of its neck, and also a snake for a tail. According to biology, the chimera is a natural or artificial development of one individual organism containing cells from another. For obvious reasons, scientists are fascinated by chimeras.

According to National Geographic, there are two different methods to make a chimera. The first way is to introduce the organs of one animal into another. It's risky, as the host’s immune system might cause the organ to be rejected. The other way is to introduce one animal’s cells into the embryo of another at an embryonic level and let them develop together into a hybrid. That can be done intentionally in a lab, or can also occur accidentally — such as that time a man failed his paternity test as a result of absorbing his twin in the womb.

Concerning the pig-human hybrid, Belmonte said:

“The ultimate goal of chimeric research is to learn whether we can use stem-cell and gene-editing technologies to generate genetically-matched human tissues and organs, and we are very optimistic that continued work will lead to eventual success.” He added, “But in the process, we are gaining a better understanding of species evolution as well as human embryogenesis and disease that is difficult to get in other ways.”

The hybrid embryos for the pig-human hybrid experiment were terminated after twenty-eight days of development to avoid more ethical concerns. Debate on the ethics is expected to continue. The National Institutes of Health (NIH) previously issued a moratorium on human chimera experimentation, though it is now considering reversing the ban.

Proponents of the research claim that the experimentation is justified because twenty-two people die every day in the US waiting for an organ transplant and somebody new is added to a donor list every ten minutes.

The team’s project was published in Cell. In the video below, the researchers discuss their results:

Reference: Truth Theory